In order to communicate with a network, a wireless user equipment (UE) needs to acquire uplink and downlink resources for such communications. A UE initiates a connection with a network when it has data to transmit on the uplink or when it is made aware that there is downlink data to be received. If the UE has no connection with the network the UE may initiate a connection via a contention based channel where transmissions from various UEs may collide. In other cases, a UE with an established connection to the network may not have dedicated resources available to transmit user data on the uplink and may request resources to transmit the user data using either a contention based uplink channel or a dedicated uplink control channel. For example, in a 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) system, this is typically done through physical uplink control channel (PUCCH) resources, when dedicated resources are provided to each UE communicating with the network element, or through a contention based physical random access channel (PRACH) between the UE and the network element when the UE is not provided with a PUCCH. The use of a dedicated uplink control channel for uplink resource requests limits the number of UEs that can be served by a network element, since such dedicated resources are scarce while time sharing these dedicated resources will result in significant latency if these resources are shared by a large number of UEs. If a random access channel is used instead of a dedicated channel, the likelihood of collisions between different transmitting UEs increases as the number of UEs utilizing such random access resource increases.
Further, each UE runs different applications and may have different data needs. In particular, a UE that is streaming audio or video may use significant data resources. However, other data devices may have applications that only sporadically exchange data. Thus, these UEs generate small bursts of sporadic traffic, followed by a period of inactivity. The sporadic traffic pattern may be present for an extended period of time, perhaps for as long as the UE is powered on. This pattern of behaviour, often referred to as a low-activity traffic, may be generated, for example, by background applications.
The increased adoption of smartphones results in an increasing number of UEs with diverse data applications (DDA) and correspondingly diverse traffic demands. While existing radio resource management mechanisms, such as those of the 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) systems, may be efficient in handling continuous streams of traffic for multimedia applications, such systems are less efficient for supporting low activity traffic from a number of always connected wireless devices such as smartphones, tablets, laptop computers and remote sensors.